Gastrointestinal System >
Clostridium Difficile Infection (CDI)
“Highly infectious spore-forming and toxin-producing gram positive anaerobic bacillus, which causes an important hospital-acquired infection responsible for 20-30% of antibiotic-associated colitis”
- Antibiotic use (within the last 2 weeks)
- Especially fluoroquinolones, clindamycin and broad-spectrum penicillins and cephalosporins.
- Multiple antibiotics or long duration of antibiotics also increases risk.
- Age ≥65
- Severe underlying comorbidities
- Gastric acid suppression (e.g. PPI medication)
- Enteral feeding GI surgery
- There are toxigenic (exotoxin producing) and non-toxigenic (cannot produce exotoxins) strains of C. difficile.
- Non-toxigenic strains are found in around 2% of healthy adults as commensals in the bowel.
- Only toxigenic strains cause disease.
- C. difficile spreads via spores released from asymptomatic or symptomatic carriers of the pathogen.
- These spores are highly infectious and resistant to acid, heat and antibiotics
- Antibiotics disrupt normal colonic microbiota, which usually compete with C. difficile.
- Toxigenic strains of C difficile are resistant to antibiotics and are able to multiply and release toxins → pseudomembranous colitis (appearance on endoscopy).
- Toxins cause colonic inflammation, intestinal fluid secretion, mucosal damage, neutrophil activation
- Watery diarrhoea (≥3 loose bowel motions within 24 hours)
- Abdominal pain
- Nausea & fever.
- No systemic features,
- ≤3 bowel motions per day
- Normal WCC
- 3-5 bowel motions
- Raised WCC
- WCC > 15×109
- Raised creatinine
- Fever >38.5 or evidence of severe colitis.
- Ileus (partial or complete)
- Toxic megacolon
- CT evidence of severe disease
- WCC (↑)
- Routine bloods (FBC, U&Es, LFTs)
- Blood cultures
- VBG (lactate)
- Abdominal X-ray
- CT abdomen pelvis (if severe disease)
- Flexible sigmoidoscopy (usually avoided)
- C. difficile toxin in stool – NAAT (nucleic acid amplification testing
- EIA (enzyme immunoassay e.g. enzyme glutamate dehydrogenase))
- C. difficile antigen in stool (only shows exposure, not active infection)
- Isolate within 2 hours
- Gloves and aprons
- Hand washing with soap and water
- Test immediately.
- Correct fluid losses.
- Stop current antibiotics.
- Metronidazole PO for 10-14 days
- Vancomycin PO for 10-14 days.
- Switch to fidaxomicin or add metronidazole if no improvement at 7 days.
- Vancomycin PO and metronidazole PO.
- IV metronidazole if ileus.
- Recurrent CDI:
- Faecal microbiota transplantation (FMT)
- Toxic megacolon (>6cm)
- Bowel perforation